Questions have been swirling around why hedge-fund tycoon and Democrat mega-donor Tom Steyer didn’t disclose his role in a controversial campaign to get state and local governments to file climate change lawsuits against energy companies.

Frustrated that nobody seems to care about climate change, “the country’s biggest individual political donor during the 2014 election cycle,” has pledged even more in 2016. Tom Steyer spent nearly $75 million in the 2014 midterms, reports Politico. He intends to “open his wallet even wider” now.